The present invention relates to a seat recliner which allows a seat back to be rotated relative to a seat cushion, and, more specifically, to one suitable for a vehicle such as an automobile.
A conventional kind of a seat recliner has been known. The seat recliner includes a frame mounted to the base plate of a seat cushion. The recliner includes a lid mounted to an arm plate of a seat back. The frame and the lid are rotatable relative to each other. The frame includes a lock tooth with an external gear. The lid includes an internal gear formed on the inner peripheral face. The external and internal gears are meshed to prevent the relative rotation between the frame and the lid.
The frame includes a pivot for supporting the lock tooth. The lock teeth allow the external and internal gears to be meshed with each other.
The frame includes a guide for guiding the lock tooth to be pivoted on the pivot.
The pivot has a base, or a connecting portion with the frame, where maximum load occurs. The greater connecting area of the pivot and the frame is superior in strength. However, a greater connecting area causes the projecting length to be lowered. The contact area of the pivot with the lock tooth is reduced, lowering the pivot in strength.
Rotational force is converted into straight external force to be exerted on the lock tooth via the internal and external gears. The pivot and lid retain the lock tooth between them to lock with each other without rotating.
The greater the rigidity of the guide is to the external force, that is, the more difficulty with which the guide is resiliently deformed against the external force, the more securely the pivot is backed up, thus improving strength. However, when guide has greater rigidity than the pivot, the pivot starts to be deformed, while the guide is not deformed. Internal force is exerted on the pivot to be deformed. The exertion causes the pivot to be damaged. Thus, the providing of the guide to improve strength obtains insufficient effect.
The thickening of the lock tooth or the use of high quality material may improve the lock tooth in rigidity against the internal force. However, this deteriorates formability and causes high productive cost.
The invention is directed to a seat recliner, which improves a pivot in strength and reduces in productive cost.
The first aspect of the invention provides a seat recliner. The seat recliner includes a first seat member. The seat recliner includes a second seat member rotatable relative to the first seat member. The seat recliner includes an input cam member for rotating relative to the first seat member. The seat recliner includes a pivot on the first seat member. The seat recliner includes a follower member for being actuated by the input cam member to lock the second seat member relative to the first seat member. The follower member includes a first side. The first side includes a tooth for meshing with the second seat member. The first side includes an engagement side pivotably engaging on the pivot. The follower member includes a second side in proximity to the engagement side. The seat recliner includes a pair of guides on the first seat member. Guides have the pivot interposed therebetween for cooperating with the pivot to pivotably support the follower member on the pivot. A guide has smaller rigidity than the pivot for retaining the second side.
Preferably, the seat recliner further includes a reinforcement member interconnecting the pivot and the first seat member. The reinforcement member includes a first support face for supporting the follower member.
Preferably, the pivot includes a second support face extending from the reinforcement member for supporting the follower member, the second support face disposed rearward of the first support face.
Preferably, the follower member includes a first engagement face for engaging the first support face. The follower member includes a second engagement face supported for engaging the second support face. The second engagement face is disposed forward of the first engagement face.
Preferably, the first engagement face contacts the first support face. The second engagement face is spaced from the second support face for being brought into contact with the second support face under a force.
Preferably, the guide includes a back-up face to contact with the follower member. The back-up face includes a recess.
Preferably, the back-up face is reduced in contact area with the follower member, so that the guide has smaller rigidity than the pivot.
Preferably, the guide includes a depression positioned differently from the back-up face.
Preferably, the back-up face is spaced away from the follower member.
The second aspect of the invention provides a seat recliner. The seat recliner includes a first seat member. The seat recliner includes a second seat member rotatable relative to the first seat member. The seat recliner includes an input cam member for rotating relative to the first seat member. The reclining mechanism includes a pivot on the first seat member. The seat recliner includes a follower member for actuated by the input cam member to lock the second seat member relative to the first seat member. The follower member includes a first side. The first includes a tooth for meshing with the second seat member. The first side includes an engagement side pivotably engaging on the pivot. The follower member includes a second side in proximity to the engagement side. The seat recliner includes a pair of guides on the first seat member. Guides have the pivot interposed therebetween for cooperating with the pivot to pivotably support the follower member on the pivot. A guide has smaller rigidity than the pivot for retaining the second side. The guide is spaced from the second side for retaining the second side under a force.
Preferably, the follower member includes a third side angularly separated from the first side around the pivot and concentric with the second side for sliding on the guide.